These are the exponents on 2 in numbers of the form (2^r)*(11^s) in the main sequence.
Table of n, a(n) for n=1..11.
A217413(1)=(2^71)*(11^5), so this sequence's first term is 71.
Cf. A217413, A217415.
Sequence in context: A127316 A322444 A339700 * A159025 A033245 A139914
Adjacent sequences: A217411 A217412 A217413 * A217415 A217416 A217417
James G. Merickel, Oct 02 2012